Jay Baruchel arrives in Los Angeles to visit with old friend and fellow actor Seth Rogen, who invites him to attend a housewarming party hosted by James Franco. Baruchel is uncomfortable being around so many people he hardly knows, so Rogen accompanies him to a convenience store for cigarettes. At the store, beams of blue light come down from the sky and carry away numerous people. Rogen and Baruchel flee back to Franco’s house amid mass chaos, but find the party undisturbed. Moments later, the earth shakes and the partygoers rush outside. A large hole opens in Franco’s yard, swallowing several partygoers, while Rogen, Baruchel, Franco, Jonah Hill, and Craig Robinson survive. They take inventory of their supplies, set up a ration system, fortify the house, and await help. The next morning, Danny McBride wakes up first. Unaware of the crisis, he wastes much of their food. The others tell him of the previous night’s events, which he initially doesn’t believe until an outsider is decapitated in front of them. Tensions rise due to various conflicts, including Baruchel and Rogen’s growing estrangement, and the others’ skepticism of Baruchel’s belief that the disaster might be the Apocalypse predicted in the Book of Revelation. Later, Emma Watson, another survivor of the party, returns. However, due to a misunderstanding, she believes the group is planning to rape her and leaves, taking the group’s remaining drinks with her. Robinson is chosen to travel outside to the basement for water, but finds the door is locked and returns after an encounter with an unknown being. Robinson’s experience causes him to believe Baruchel’s theory that it is the Apocalypse. They reach the basement by digging through the floor and find the water, but McBride ends up wasting most of it out of spite. The group unanimously decides to kick McBride out of the house. Franco gives him the revolver, which he tries to use to kill the others, only to find that it is filled with blanks. Before he leaves, McBride reveals that Baruchel was in town two months prior, but stayed at a hotel instead of Rogen’s house due to their strained friendship. Later that night, Hill prays for Baruchel to die and is raped by a demon. The next day, Robinson and Baruchel go to a neighboring home for supplies. Meanwhile, Franco and Rogen find Hill unconscious from what looks like an LBS episode, but he wakes up possessed. Hill chases Franco and Rogen while Robinson and Baruchel flee a demonic bull at the neighbor’s house. The group subdues Hill, but during an exorcism attempt, Baruchel and Rogen get into a fight and knock a candle over. A fire starts, engulfing Hill and the house in flames and forcing the remaining four outside. Franco suggests taking his car to his home in Malibu, but finds the car guarded by a winged demon. Robinson volunteers to sacrifice himself. The plan succeeds and Robinson is raptured. As the others escape, the car is hit by an armored motor home filled with cannibals led by Danny McBride, along with Channing Tatum as his pet, and they are captured. Franco volunteers to sacrifice himself to save the others, but taunts McBride as he ascends to Heaven, causing the beam to vanish. Franco is eaten by McBride and his cannibals as Rogen and Baruchel escape. They encounter Satan, and reconcile. As they await death in an embrace, a blue beam strikes Baruchel, and he begins to ascend but not Rogen. Baruchel grabs Rogen’s hand, but Rogen’s presence prevents them from ascending into Heaven, so Rogen lets go to save his friend. As he falls into Satan’s mouth, he is saved by another beam, which splits Satan down the middle. In Heaven, Robinson, who is now an angel, tells them that Heaven is a place where any desire comes true. Baruchel wishes for the Backstreet Boys and the band performs “Everybody (Backstreet’s Back)” as everyone dances.